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Cloud Computing – Service Models

Cloud Computing – Service Models

Cloud computing architecture refers to the components and subcomponents required for cloud computing. These components typically consist of a front end platform (fat client, thin client, mobile device), back end platforms (servers, storage), a cloud based delivery, and a network (Internet, Intranet, Intercloud). Combined, these components make up cloud computing architecture.

A cloud infrastructure is the collection of hardware and software that enables the five essential characteristics of cloud computing. The cloud infrastructure can be viewed as containing both a physical layer and an abstraction layer. The physical layer consists of the hardware resources that are necessary to support the cloud services being provided, and typically includes server, storage and network components. The abstraction layer consists of the software deployed across the physical layer, which manifests the essential cloud characteristics. Conceptually the abstraction layer sits above the physical layer

Infrastructure as a service (IaaS)

The capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications (Peter and Timothy, 2012). The IaaS model may include the following elements: Processing, Storage, and Network (Larry and Shivaramakrishnan, 2014). The consumer does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, and deployed applications; and possibly limited control of select networking components (e.g., host firewalls) (Juscelino and Louis, 2014).

Platform as service (PaaS)

The capability provided to the user is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages, libraries, services, and tools supported by the provider (Peter and Timothy, 2012). The PaaS model includes services that build on IaaS services. They add value to the IaaS services by providing a platform in which the cloud users can provision their own applications, or conduct application development activities. Services are provisioned in PaaS models: Middleware, Application servers, Database servers, Portal servers, and Development runtime environments (Larry and Shivaramakrishnan, 2014). The user does not manage or control the underlying cloud infrastructure including network, servers, operating systems, or storage, but has control over the deployed applications and possibly configuration settings for the application-hosting environment.

The platform, consists of three components: the operating system; the application development environment; and the database.

  1. The operating system (OS). Today’s technology makes it possible to use a computer that doesn’t have an OS at all. The OS is obtainable from the cloud and can become a Cloud Computing service as well.
  2. The application development environment such as .Net technology from Microsoft (“Azure” the new name for the Cloud Computing foundation by Microsoft) or Sandbox by Google.
  3. The database may be an open source DBMS (data base management system) like MySQL or a proprietary database like Microsoft SQL Server or Oracle.

Software as a service (SaaS)

The SaaS model provides software services that are complete applications that are ready to use (Larry and Shivaramakrishnan, 2014). The capability provided to the consumer is to use the provider’s applications running on a cloud infrastructure. The applications are accessible from various client devices through either a thin client interface, such as a web browser (e.g., web-based email), or a program interface. The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings (Peter and Timothy, 2012).

There are two main models for working with the cloud.  The first is free of charge.  This model usually has two implications: a. the user is exposed to commercials; b. there is no service agreement between the user and the supplier in terms of support, service, backup, data security etc. The most famous examples of this model are Gmail and Facebook. If one deletes some information by mistake there is no support by the provider and there is almost no way to recover the data. With the second model, the user has to pay for the service.  When using the Salesforce cloud application for instance, the user can choose between three different service level agreements (SLA), (1) basic support; (2) premier support; and (3) premier support with administration. Charges to the user are based on the level of service.  The user feels much more secure knowing there is an SLA with the supplier.

Benefits of the Cloud

Cloud computing providing so many benefits to the users i.e. it reduces software maintaining cost, managing growth of resources, providing cheaper way to performs calculation etc. (Jagdeep, 2014). Storage cloud can help businesses achieve more effective functionality at a lower cost while improving business agility and reducing project scheduling risk (Larry & Shivaramakrishnan, 2014).


  1. Peter Mell and Timothy Grance (2012), “The NIST Definition of Cloud Computing – Recommendations of the National Institute of Standards and Technology”, NIST, [Online] Available: , Retrieved 28 October 2014.
  2. Larry Coyne, Shivaramakrishnan Gopalakrishnan, and John Sing (2014), “IBM Private, Public, and Hybrid Cloud Storage Solutions” [Online] Available:, Retrieved 28 October 2014
  3. Juscelino Candido, and Louis Fuka (2014), “Move to the Cloud Easily with IBM SmartCloud Entry V3.1 and IBM Common Cloud Stack” [Online] Available:, Retrieved 28 October 2014
  4. Jagdeep Singh (2014),”CLOUD COMPUTING : AN ANALYSIS OF SECURITY ISSUES”, VSRD International Journal of Computer Science &Information Technology, Vol. 4, Issue 3,  Pages 41-46, e-ISSN :2231-2471, p-ISSN :2319-2224,